Microelectromechanical switching device

Abstract

The present application provides a micro-electro-mechanical switch device, comprising a first substrate, a second substrate, a bonding structure, a signal trace and a switch structure. The second substrate comprises a plurality of actuation electrodes separated from each other. The bonding structure bonds the first substrate and the second substrate. There is a working space between the first substrate, the second substrate and the bonding structure. The signal trace is disposed on the first substrate or the second substrate. The switch structure is disposed on the second substrate and located in the working space. The switch structure is provided corresponding to the plurality of actuation electrodes. When the plurality of actuation electrodes receives differentiated driving conditions, the switch structure switches from an off state to an on state towards the signal trace in a progressive manner. The micro-electro-mechanical switch device of the present application can improve the creep effect, thereby improving the structural reliability and service life.

Description

Technical Field

[0001] This invention relates to a switching device, and more particularly to a microelectromechanical switching device. Background Technology

[0002] Current microelectromechanical switches (MEMS) typically use a large, flat bottom electrode to generate electrostatic force. A bias voltage is applied to attract the switch structure downwards, such as a cantilever beam or arch bridge type, causing its contacts to make contact with the signal line and achieve an ON state. However, because the electrostatic attraction is inversely proportional to the square of the electrode spacing, the electrostatic force experienced by the switch structure at the moment of downward attraction is extremely large. This causes the switch structure to fail to stop immediately upon contact with the signal line, resulting in multiple physical bounces. This bounce not only causes the switch to perform multiple unexpected on / off cycles within a short period, requiring a longer time to turn off, but also subjectes the contacts to tremendous physical impact, significantly reducing product lifespan and reliability. Summary of the Invention

[0003] This invention relates to a microelectromechanical switching device that can improve creep effect, thereby enhancing structural reliability and service life.

[0004] According to an embodiment of the present invention, a microelectromechanical switching device includes a first substrate, a second substrate, a bonding structure, signal traces, and a switching structure. The second substrate includes a plurality of actuating electrodes separated from each other. The bonding structure joins the first substrate and the second substrate. A working space exists between the first substrate, the second substrate, and the bonding structure. The signal traces are disposed on the first substrate or the second substrate. The switching structure is disposed on the second substrate and located in the working space. The switching structure is disposed corresponding to the plurality of actuating electrodes. When the plurality of actuating electrodes receive differentiated driving conditions, the switching structure progressively switches from an off state to an on state toward the signal traces.

[0005] In the microelectromechanical switching device according to an embodiment of the present invention, the above-mentioned differentiated driving conditions satisfy one of the following conditions: (1) different bias signals are applied to multiple actuating electrodes at the same time; (2) the same bias signal is applied to multiple actuating electrodes at different times; and (3) the same bias signal is applied to multiple actuating electrodes with different apertures at the same time.

[0006] In a microelectromechanical switching device according to an embodiment of the present invention, the first substrate includes a first base and a plurality of first conductive vias. The plurality of first conductive vias are capable of transmitting signals. The plurality of first conductive vias penetrate the first base, and signal traces connect to the plurality of first conductive vias and are disposed on the first base of the first substrate. The second substrate further includes a second base and a plurality of second conductive vias. The plurality of second conductive vias penetrate the second base. The plurality of second conductive vias are plurality of actuating electrodes. A bonding structure joins the first base of the first substrate and the second base of the second substrate, such that the switching structure contacts the signal traces to form a conducting state. When the plurality of actuating electrodes receive differentiated driving conditions, the switching structure gradually moves toward the signal traces, switching from an off state to a conducting state.

[0007] In the microelectromechanical switching device according to an embodiment of the present invention, the switching structure includes a contact bump portion, two support portions, and a connecting portion. The contact bump portion is arranged corresponding to the signal trace. The two support portions are fixed to a second substrate. The connecting portion connects the contact bump portion and the two support portions.

[0008] In the microelectromechanical switching device according to an embodiment of the present invention, the above-described engagement structure has a first thickness, the contact protrusion portion has a second thickness, each of the two support portions has a third thickness, and the value of the first thickness is less than the value of the second thickness plus the value of the third thickness.

[0009] In the microelectromechanical switching device according to an embodiment of the present invention, the value of the second thickness plus the third thickness minus the first thickness is less than the value of the third thickness.

[0010] In the microelectromechanical switching device according to an embodiment of the present invention, the contact bump portion includes a base, a filler bump, a metal layer, and a contact layer. The base is connected to the connecting portion, and the filler bump is disposed on the base. The metal layer is disposed on the base and covers the filler bump. The contact layer is disposed on the metal layer.

[0011] In the microelectromechanical switching device according to an embodiment of the present invention, the hardness of the contact layer is greater than the hardness of the metal layer.

[0012] In the microelectromechanical switching device according to an embodiment of the present invention, the hardness of the contact layer is greater than the hardness of the signal trace.

[0013] In the microelectromechanical switching device according to an embodiment of the present invention, the orthographic projections of the contact bump portion and the connecting portion on the second substrate overlap with a plurality of actuating electrodes. The plurality of actuating electrodes are located inside the orthographic projections of the two supporting portions on the second substrate.

[0014] In the microelectromechanical switching device according to an embodiment of the present invention, the orthogonal projection of the plurality of first conductive vias connected by the signal traces described above onto the second substrate is located outside the plurality of actuating electrodes.

[0015] In the microelectromechanical switching device according to an embodiment of the present invention, the second substrate further includes a substrate and a plurality of first conductive vias and a plurality of second conductive vias separated from each other. The plurality of first conductive vias and the plurality of second conductive vias respectively penetrate the substrate. The plurality of first conductive vias are capable of transmitting signals. The plurality of second conductive vias are a plurality of actuating electrodes. The plurality of actuating electrodes are located inside the plurality of first conductive vias. Signal traces are disposed on the substrate of the second substrate and connect to the plurality of first conductive vias. The switching structure includes contact bump portions. The contact bump portions are disposed corresponding to the signal traces to form an off state. When the plurality of actuating electrodes receive differentiated driving conditions, the switching structure gradually contacts the signal traces and switches from the off state to the on state.

[0016] In the microelectromechanical switching device according to an embodiment of the present invention, the above-described switching structure further includes a support portion and a connecting portion. The support portion is fixed to a substrate and connects to a plurality of first conductive vias located on the side opposite to the signal trace. The connecting portion connects the contact bump portion and the support portion.

[0017] In the microelectromechanical switching device according to an embodiment of the present invention, the contact bump portion includes a base, a filler bump, a metal layer, and a contact layer. The base is connected to the connecting portion, and the filler bump is disposed on the base. The metal layer is disposed on the base and covers the filler bump. The contact layer is disposed on the metal layer.

[0018] In the microelectromechanical switching device according to an embodiment of the present invention, the hardness of the contact layer is greater than the hardness of the metal layer.

[0019] In the microelectromechanical switching device according to an embodiment of the present invention, the hardness of the contact layer is greater than the hardness of the signal trace.

[0020] In the microelectromechanical switching device according to an embodiment of the present invention, the orthographic projection of the aforementioned connection portion on the substrate overlaps with a plurality of actuating electrodes.

[0021] Based on the above, in the design of the microelectromechanical switching device of the present invention, the second substrate includes multiple actuating electrodes, and the switching structure is disposed corresponding to the multiple actuating electrodes. Therefore, when the multiple actuating electrodes receive differentiated driving conditions, the switching structure can progressively move towards the signal trace, switching from the off state to the on state. This allows for control of the movement process of the switching structure, suppression of bouncing, and improvement of creep effects, thereby enhancing the structural reliability and service life of the microelectromechanical switching device of the present invention. Attached Figure Description

[0022] Figure 1A This is a top view schematic diagram of a microelectromechanical switching device according to an embodiment of the present invention;

[0023] Figure 1B It is along Figure 1A A schematic cross-sectional view of line II in the conducting state;

[0024] Figure 1C It is along Figure 1A A schematic cross-sectional view of line II in the off state;

[0025] Figure 2A This is a top view schematic diagram of a microelectromechanical switching device according to another embodiment of the present invention;

[0026] Figure 2B It is along Figure 2A A schematic cross-sectional view of line II-II in the conducting state;

[0027] Figure 2C It is along Figure 2A A schematic cross-sectional view of line II-II in the off state.

[0028] Explanation of icon numbers

[0029] 100a, 100b: Microelectromechanical switching devices;

[0030] 110a, 110b: First substrate;

[0031] 112: First basement;

[0032] 114: First conductive via;

[0033] 120a, 120b: Second substrate;

[0034] 122: Second basement / basement;

[0035] 123: First conductive via;

[0036] 124: Actuation electrode / second conductive via;

[0037] 130a, 130b: Joint structure;

[0038] 140a, 140b: Signal traces;

[0039] 150a, 150b: Switch structure;

[0040] 152a, 152b: Contact protrusions;

[0041] 154a, 154b: Support parts;

[0042] 156a, 156b: Connecting parts;

[0043] B, B': base;

[0044] C, C': Contact layer;

[0045] M, M': Metal layers;

[0046] P, P': Filled bumps;

[0047] S, S': Workspace;

[0048] T1: First thickness;

[0049] T2: Second thickness;

[0050] T3: Third thickness. Detailed Implementation

[0051] Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same element references are used in the drawings and description to denote the same or similar parts.

[0052] The embodiments of the present invention can be understood in conjunction with the accompanying drawings, which are also considered part of the disclosure. It should be understood that the drawings of the present invention are not drawn to scale; in fact, the dimensions of the components may be arbitrarily enlarged or reduced to clearly illustrate the features of the present invention.

[0053] Unless otherwise expressly stated, the directional terms used in this document (e.g., up, down, left, right, front, back, top, bottom) are for reference only and are not intended to imply absolute orientation.

[0054] Figure 1A This is a top view schematic diagram of a microelectromechanical switching device according to an embodiment of the present invention. Figure 1B It is along Figure 1A A schematic cross-sectional view of line II in the conducting state. Figure 1C It is along Figure 1A A schematic cross-sectional view of line II in the off state. For clarity, Figure 1A Some layers are omitted, such as the outer metal layer on the first substrate.

[0055] Please also refer to Figure 1A , Figure 1B as well as Figure 1C In this embodiment, the microelectromechanical switching device 100a includes a first substrate 110a, a second substrate 120a, a bonding structure 130a, a signal trace 140a, and a switching structure 150a. The second substrate 120a includes a plurality of actuating electrodes 124 separated from each other. The bonding structure 130a bonds the first substrate 110a and the second substrate 120a. A working space S is provided between the first substrate 110a, the second substrate 120a, and the bonding structure 130a. The signal trace 140a is disposed on either the first substrate 110a or the second substrate 120a. Figures 1A to 1CIn this embodiment, signal trace 140a is disposed on a first substrate 110a. Switch structure 150a is disposed on a second substrate 120a and located in the working space S. Switch structure 150a is provided with a plurality of actuation electrodes 124. When the plurality of actuation electrodes 124 receive differentiated driving conditions, switch structure 150a gradually moves toward (contacts) signal trace 140a, switching from an off state to an on state.

[0056] In one embodiment, the first substrate 110a and the second substrate 120a may each be a wafer (e.g., a silicon wafer), wherein the first substrate 110a and the second substrate 120a are fabricated separately and then joined together by a bonding structure 130a to form a microelectromechanical switch device 100a. In another embodiment, the first substrate 110a and the second substrate 120a may each be a substrate (e.g., glass or other material, non-circular in shape), wherein the first substrate 110a and the second substrate 120a are fabricated separately and then joined together by a bonding structure 130a to form a microelectromechanical switch device 100a. In yet another embodiment, the first substrate 110a and the second substrate 120a may each be a wafer and a substrate, respectively, wherein the first substrate 110a and the second substrate 120a are fabricated separately and then joined together by a bonding structure 130a to form a microelectromechanical switch device 100a.

[0057] In this embodiment, the signal trace 140a is disposed on the first substrate 110a (the side of the first substrate 110a facing the second substrate 120a), while the switch structure 150a and the actuation electrode 124 are disposed on the second substrate 120a. That is, the signal trace 140a and the switch structure 150a and the actuation electrode 124 belong to different substrates (i.e., the first substrate 110a and the second substrate 120a). In one embodiment, the signal trace 140a may be, for example, a high-frequency signal layer, such as a radio frequency signal layer. Compared to the prior art that integrates the switch structure, actuation electrode and signal trace on a single wafer, the microelectromechanical switching device 100a of this embodiment can reduce process complexity and effectively improve signal transmission quality.

[0058] Furthermore, in this embodiment, the first substrate 110a includes a first base 112 and a plurality of first conductive vias 114. The plurality of first conductive vias 114 are capable of transmitting signals. The plurality of first conductive vias 114 penetrate the first base 112, and signal traces 140a connect the plurality of first conductive vias 114 and are disposed on the first base 112 of the first substrate 110a. On the other hand, the second substrate 120a also includes a second base 122 and a plurality of second conductive vias 124. The plurality of second conductive vias 124 penetrate the second base 122. The plurality of second conductive vias 124 are a plurality of actuation electrodes 124. In one embodiment, the plurality of actuation electrodes 124 may have the same aperture. In one embodiment, some of the plurality of actuation electrodes 124 may have different apertures.

[0059] In one embodiment, the material of the first substrate 112 of the first substrate 110a and the material of the second substrate 122 of the second substrate 120a can be the same. For example, the first substrate 112 of the first substrate 110a and the second substrate 122 of the second substrate 120a can be, for example, pure single-crystal silicon, silicon substrate, glass substrate, glass, or sapphire. In one embodiment, the resistance value of the first conductive via 114 can be lower than the resistance value of the second conductive via 124. For example, in an embodiment where the first conductive via 114 and the second conductive via 124 are made of the same material, the first conductive via 114 can have a larger aperture or a smaller thickness, so that the resistance value of the first conductive via 114 can be lower than the resistance value of the second conductive via 124. In an embodiment where the aperture and thickness of the first conductive via 114 and the second conductive via 124 are the same, the first conductive via 114 can be made of a material with a lower resistance value, so that the resistance value of the first conductive via 114 can be lower than the resistance value of the second conductive via 124. This configuration is because the first conductive via 114 is responsible for transmitting radio frequency (RF) signals, and its lower resistance helps reduce signal loss. Therefore, the resistance value of the first conductive via 114 is lower than that of the second conductive via 124, which optimizes the different transmission requirements of high-frequency signals and DC bias voltage. The first conductive via 114 can transmit external transmission signals to the signal trace 140a, while the second conductive via 124 can receive external control signals and act as an actuation electrode 124. That is, in this embodiment, the transmission signal and the control signal are transmitted through the first conductive via 114 and the second conductive via 124, respectively. By spatially separating the high-frequency signal path and the DC control path (the high-frequency signal path is located on the first substrate 110a, while the DC control path is located on the second substrate 120a), the interference of the control signal on the RF signal can be reduced, and the signal leakage and loss caused by parasitic effects can be reduced, thereby improving the RF isolation and signal integrity of the microelectromechanical switching device 100a.

[0060] Furthermore, in this embodiment, the bonding structure 130a bonds the first substrate 112 of the first substrate 110a and the second substrate 122 of the second substrate 120a, so that the switch structure 150a contacts the signal trace 140a to form a conductive state. That is, the microelectromechanical switch device 100a in this embodiment is a normally ON type of ohmic contact MEMS switch. In this embodiment, the bonding structure 130a can bond the first substrate 110a and the second substrate 120a using wafer-level bonding technologies such as polymer bonding, eutectic bonding, or hybrid bonding, so that the switch structure 150a contacts the signal trace 140a to form a conductive state. In one embodiment, the material of the bonding structure 130a is, for example, a conductive bonding material or an insulating bonding material.

[0061] Please refer to this again. Figure 1B as well as Figure 1C The switch structure 150a of this embodiment includes a contact bump portion 152a, two support portions 154a, and a connecting portion 156a. The contact bump portion 152a is disposed corresponding to the signal trace 140a. The two support portions 154a are fixed to the second base 122. The connecting portion 156a connects the contact bump portion 152a and the two support portions 154a. That is, the switch structure 150a is specifically embodied as a bridge-like (Clamped-Clamped Beam) structure. This double-ended fixed configuration can provide higher structural rigidity and faster recovery speed.

[0062] like Figure 1B as well as Figure 1C As shown, in this embodiment, the orthographic projections of the contact bump portion 152a and the connecting portion 156a on the second base 122 overlap with the plurality of actuating electrodes 124, meaning that the contact bump portion 152a and the connecting portion 156a are provided corresponding to the actuating electrodes 124. The plurality of actuating electrodes 124 are located inside the orthographic projections of the two support portions 154a on the second base 122, meaning that the two support portions 154a are located outside the actuating electrodes 124. In other words, in the orthographic projections on the second base 122, the support portions 154a in this embodiment are located on the outermost side, and no other components are provided outside them. The orthographic projections of the plurality of first conductive vias 114 connected by the signal trace 140a on the second base 122 are located outside the plurality of actuating electrodes 124, meaning that the plurality of first conductive vias 114 are located outside the actuating electrodes 124.

[0063] The contact bump portion 152a of this embodiment may include a base B, a filling bump P, a metal layer M, and a contact layer C. The base B is connected to the connecting portion 156a, and the filling bump P is disposed on the base B. The metal layer M is disposed on the base B and covers the filling bump P. The contact layer C is disposed on the metal layer M. In one embodiment, the material of the filling bump P may be, for example, metal or base alloy. In one embodiment, the material of the filling bump P may be, for example, gold alloy or polysilicon. In one embodiment, the material of the metal layer M is different from that of the filling bump P, which can reduce costs. In one embodiment, the metal layer M and the filling bump P may be made of the same material. In one embodiment, the metal layer M is, for example, a gold layer. In one embodiment, the hardness of the contact layer C can be greater than that of the metal layer M, thereby ensuring that the contact bump portion 152a can maintain structural integrity and stable contact resistance when repeatedly abutting against the signal trace 140a. In one embodiment, the hardness of the contact layer C is greater than that of the signal trace 140a. In one embodiment, the material of the contact layer C is, for example, a platinum group metal, such as platinum, palladium, rhodium, ruthenium, iridium, osmium, or a metal oxide, such as ruthenium dioxide, thereby reducing structural wear caused by repeated impacts while maintaining good electrical conductivity.

[0064] In summary, the contact bump portion 152a of the present embodiment is composed of the base B, the filling bump P, the metal layer M, and the contact layer C. Through the design of the multi-layer composite structure, the contact bump portion 152a not only has good electrical conductivity, but also can withstand long-term physical contact stress and is not prone to damage. In one embodiment, the orthographic projection of the contact bump portion 152a on the second substrate 122 at least partially overlaps the second conductive via 124, which helps to apply electrostatic force most directly to the region below the contact bump portion 152a, thereby maximizing pull-down efficiency and reducing the requirement for driving voltage. On the other hand, the orthographic projection of the connecting portion 156a on the second substrate 122 at least partially overlaps the second conductive via 124.

[0065] Please further refer to Figure 1B , in this embodiment, the bonding structure 130a has a first thickness T1, the contact bump portion 152a has a second thickness T2, each support portion 154a has a third thickness T3, and the value of the first thickness T1 is less than the sum of the second thickness T2 and the third thickness T3, that is, T1< (T2+T3), which can ensure that the bonding height of the bonding structure 130a does not exceed the total height of the switch structure 150a, so as to achieve physical contact between the contact bump portion 152a and the signal trace 140a. In addition, the value obtained by subtracting the first thickness T1 from the sum of the second thickness T2 and the third thickness T3 is less than the value of the third thickness T3, that is, (T2+T3)-T1<T3, which can ensure that there is still sufficient gap after bonding to prevent the structure from being permanently compacted, thereby ensuring that the switch structure 150a can be smoothly opened.

[0066] Please further simultaneously refer to Figure 1B as well as Figure 1C In this example, when multiple actuating electrodes 124 receive differentiated driving conditions (in this embodiment, this refers to the differentiated driving conditions received when the microelectromechanical switching device 100a has switched from a normally open conducting state to an off state and then back to a conducting state), the switching structure 150a gradually moves toward (contacts) the signal trace 140a, switching from the off state to the conducting state. In one embodiment, the aforementioned differentiated driving conditions are, for example, applying different bias voltage signals to multiple actuating electrodes 124 at the same time, that is, applying different bias voltage signals to actuating electrodes 124 in adjacent or different regions at the same time to control the electrostatic force intensity of each region (in this embodiment, this is reducing the bias voltage applied to multiple actuating electrodes 124, for example, reducing the bias voltage applied to multiple actuating electrodes 124 to zero, wherein the bias voltage-time function of the rate of decrease of the bias voltage of each actuating electrode 124 may be different). In one embodiment, the differentiated driving conditions described above may involve applying the same bias signal to multiple actuator electrodes 124 at different times (in this embodiment, the bias applied to the multiple actuator electrodes 124 is sequentially reduced to zero), which can form a wave-like process, for example. In one embodiment, the differentiated driving conditions described above may involve applying the same bias signal to multiple actuator electrodes 124 with different apertures at the same time. In one embodiment, the gradual orientation toward the signal trace 140a may be, for example, when the switch structure 150a is oriented toward the signal layer 140a, the displacement velocity of the switch structure 150a in its first operating state at a first time is greater than the displacement velocity of the switch structure 150a in its second operating state at a second time, wherein the first time is earlier than the second time. In one embodiment, a bias signal (reducing the applied bias) can be applied first to the actuating electrode 124 that is closer to the contact bump portion 152a, causing the connecting portion 156a and / or the contact bump portion 152a in the corresponding area to rise first. Then, a bias signal (reducing the applied bias) can be applied to the actuating electrode 124 that corresponds to the support portion 154a, causing the contact bump portion 152a to move upward smoothly. This can significantly reduce the force and speed when the switch structure 150a and the signal trace 140a approach each other.

[0067] Creep refers to the phenomenon where a material undergoes permanent plastic deformation under long-term stress, even if the stress has not reached the yield strength. Since each actuation electrode 124 in this embodiment can be independently controlled, the deformation pattern and stress distribution (the magnitude and distribution of stress in each region) of the switch structure 150a can be adjusted, thus avoiding excessive stress concentration in localized areas. By reducing localized stress during long-term operation, the accumulation of creep deformation in the material can be slowed down, thereby improving the long-term reliability and service life of the switch structure 150a in this embodiment.

[0068] It should be noted that the following embodiments use the component reference numerals and some content from the foregoing embodiments, with the same reference numerals used to represent the same or similar components, and descriptions of the same technical content omitted. For explanations of the omitted parts, please refer to the foregoing embodiments; these will not be repeated in the following embodiments.

[0069] Figure 2A This is a top view schematic diagram of a microelectromechanical switching device according to another embodiment of the present invention. Figure 2B It is along Figure 2A A schematic cross-sectional view of line II-II in the conducting state. Figure 2C It is along Figure 2A A schematic cross-sectional view of line II-II in the off state.

[0070] Please refer to the following at the same time. Figure 1A , Figure 1B , Figure 2A as well as Figure 2B The microelectromechanical switching device 100b in this embodiment and Figure 1A Similar to the microelectromechanical switching device 100a, the difference between the two is that in this embodiment, the signal line 140b is disposed on the second substrate 120b, while the switching structure 150b corresponding to the plurality of actuation electrodes 124 is disposed on the second substrate 120b and located in the working space S'.

[0071] Furthermore, please also refer to Figure 2A , Figure 2B as well as Figure 2C In this embodiment, the second substrate 120b further includes a base 122 and a plurality of first conductive vias 123 and a plurality of second conductive vias 124 separated from each other. The plurality of first conductive vias 123 and the plurality of second conductive vias 124 respectively penetrate the base 122. The plurality of first conductive vias 123 can transmit signals, while the plurality of second conductive vias 124 are a plurality of actuation electrodes 124. The plurality of actuation electrodes 124 are located inside the plurality of first conductive vias 123. A signal trace 140b is disposed on the base 122 of the second substrate 120b (on the side facing the first substrate 110b) and connects to the plurality of first conductive vias 123.

[0072] In this embodiment, the contact bump portion 152b of the switch structure 150b is provided corresponding to the signal trace 140b and is in an off state. When multiple actuation electrodes 124 receive differentiated driving conditions, the switch structure 150b gradually contacts the signal trace 140b and switches from the off state to the on state. In other words, the microelectromechanical switch device 100b of this embodiment is an ohmic contact MEMS switch of the normally off type.

[0073] Furthermore, the switch structure 150b in this embodiment also includes a support portion 154b and a connecting portion 156b. The support portion 154b is fixed to the base 122 of the second substrate 120b and connected to a plurality of first conductive vias 123 located on the side opposite to the signal trace 140b. The connecting portion 156b connects the contact bump portion 152b and the support portion 154b. That is, one end of the switch structure 150b (i.e., the support portion 154b) is fixed to the base 122, while the other end of the switch structure 150b (i.e., the contact bump portion 152b) is a free end, thereby forming a cantilever beam structure. This single-end fixed cantilever beam configuration substantially reduces the overall elastic constant of the structure, allowing the switch structure 150b to generate a larger displacement when facing the same electrostatic force. Here, the orthographic projection of the connecting portion 156b on the base 122 overlaps with the plurality of actuating electrodes 124, meaning that the connecting portion 156b is provided corresponding to the actuating electrodes 124.

[0074] Furthermore, such as Figure 2B as well as Figure 2C As shown, the contact bump portion 152b of this embodiment includes a base B', a filler bump P', a metal layer M', and a contact layer C'. The base B' connects to the connecting portion 156b, and the filler bump P' is disposed on the base B'. The metal layer M' is disposed on the base B' and covers the filler bump P'. The contact layer C' is disposed on the metal layer M'. In one embodiment, the filler bump P' may be made of, for example, metal or a substrate alloy. In one embodiment, the filler bump P' may be made of, for example, a gold alloy or polysilicon. In one embodiment, the metal layer M' and the filler bump P' are made of different materials, which can reduce costs. In one embodiment, the metal layer M' and the filler bump P' may be made of the same material. In one embodiment, the metal layer M' is, for example, a gold layer. In one embodiment, the hardness of the contact layer C' may be greater than the hardness of the metal layer M', thereby ensuring that the contact bump portion 152b maintains structural integrity and stable contact resistance when repeatedly abutting against the signal trace 140b. In one embodiment, the hardness of the contact layer C' is greater than the hardness of the signal trace 140b. In one embodiment, the material of the contact layer C' is, for example, a platinum group metal, such as platinum, palladium, rhodium, ruthenium, iridium, or osmium, or a metal oxide, such as ruthenium dioxide, thereby maintaining good conductivity while reducing structural wear caused by repeated impacts.

[0075] In short, the contact bump portion 152b in this example is composed of a base B', a filling bump P', a metal layer M', and a contact layer C'. Through the design of a multi-layer composite structure, the contact bump portion 152b not only has good conductivity but can also withstand long-term physical contact stress without easily being damaged. In one embodiment, the contact bump portion can also be composed of a metal layer and a contact layer, which simplifies the structure.

[0076] Please refer to the following at the same time: Figure 2B as well as Figure 2C In this example, when multiple actuating electrodes 124 receive differentiated driving conditions, the switching structure 150b gradually contacts the signal trace 140b, switching from an off state to an on state. In one embodiment, the differentiated driving conditions may involve applying different bias signals to the multiple actuating electrodes 124 simultaneously, meaning different bias signals are applied to adjacent or different regions of the actuating electrodes 124 at the same time to control the electrostatic force intensity of each region (in this embodiment, the bias applied to the multiple actuating electrodes 124 is increased). In one embodiment, the differentiated driving conditions may involve applying the same bias signal to the multiple actuating electrodes 124 at different times, which can form, for example, a wave-like process. In one embodiment, the differentiated driving conditions may involve applying the same bias signal to multiple actuating electrodes 124 with different apertures simultaneously. In one embodiment, the aforementioned progressive contact signal trace 140b is described, for example, when the switch structure 150b contacts the signal layer 140b, the displacement velocity of the switch structure 150b in its first operating state at a first time is greater than the displacement velocity of the switch structure 150b in its second operating state at a second time, wherein the first time is earlier than the second time. In one embodiment, a bias signal (increasing the applied bias) can be applied first to the actuation electrode 124 closer to the support portion 154b, causing the connection portion 156b corresponding to that area to descend first. Then, a bias signal (increasing the applied bias) can be applied to the actuation electrode 124 closer to the contact bump portion 152b, causing the contact bump portion 152b to move downward smoothly. This can significantly reduce the force and speed when the switch structure 150b contacts the signal trace 140b.

[0077] Since each actuation electrode 124 in this embodiment can be independently controlled, the deformation shape and stress distribution (the magnitude and distribution of force in each region) of the control switch structure 150b can be adjusted, thus avoiding excessive stress concentration in local areas. By reducing local stress during long-term operation, the accumulation of creep deformation of the material can be slowed down, thereby improving the long-term reliability and service life of the switch structure 150b in this embodiment.

[0078] In summary, in the design of the microelectromechanical switching device of the present invention, the second substrate includes multiple actuation electrodes, and the switching structure is arranged corresponding to the multiple actuation electrodes. Therefore, when the multiple actuation electrodes receive differentiated driving conditions, the switching structure can progressively switch from the off state to the on state by moving towards the signal trace. This allows for control of the movement process of the switching structure, suppression of bouncing, and improvement of creep effects, thereby enhancing the structural reliability and service life of the microelectromechanical switching device of the present invention.

[0079] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A microelectromechanical switching device, characterized in that, include: First substrate; The second substrate includes a plurality of actuation electrodes that are separated from each other; A bonding structure is provided to bond the first substrate and the second substrate, and a working space is provided between the first substrate, the second substrate and the bonding structure. Signal traces are disposed on the first substrate or the second substrate; as well as A switching structure is disposed on the second substrate and located in the working space, wherein the switching structure is disposed corresponding to the plurality of actuation electrodes, and when the plurality of actuation electrodes receive differentiated driving conditions, the switching structure switches from the off state to the on state by progressively moving toward the signal trace.

2. The microelectromechanical switching device according to claim 1, characterized in that, The differentiation driving condition satisfies one of the following conditions: (1) Apply different bias signals to the plurality of actuator electrodes at the same time; (2) Apply the same bias signal to the plurality of actuator electrodes at different times; as well as (3) Apply the same bias signal to the plurality of actuation electrodes with different apertures at the same time.

3. The microelectromechanical switching device according to claim 1, characterized in that, The first substrate includes a first base and a plurality of first conductive vias. The plurality of first conductive vias are capable of transmitting signals. The plurality of first conductive vias penetrate the first base, and the signal traces are connected to the plurality of first conductive vias and disposed on the first base of the first substrate. The second substrate further includes a second base and a plurality of second conductive vias, the plurality of second conductive vias penetrating the second base, wherein the plurality of second conductive vias are the plurality of actuation electrodes; The bonding structure bonds the first substrate of the first substrate and the second substrate of the second substrate, so that the switch structure contacts the signal trace to form the conduction state; as well as When the plurality of actuating electrodes receive the differentiated driving conditions, the switching structure gradually moves toward the signal line and switches from the off state to the on state.

4. The microelectromechanical switching device according to claim 3, characterized in that, The switch structure includes a contact bump portion, two support portions, and a connecting portion. The contact bump portion is arranged corresponding to the signal trace, while the two support portions are fixed on the second substrate, and the connecting portion connects the contact bump portion and the two support portions.

5. The microelectromechanical switching device according to claim 4, characterized in that, The joining structure has a first thickness, the contact protrusion has a second thickness, each of the two support portions has a third thickness, and the value of the first thickness is less than the value of the second thickness plus the value of the third thickness.

6. The microelectromechanical switching device according to claim 5, characterized in that, The value of the second thickness plus the third thickness minus the first thickness is less than the value of the third thickness.

7. The microelectromechanical switching device according to claim 4, characterized in that, The contact bump portion includes a base, a filling bump, a metal layer, and a contact layer. The base is connected to the connecting portion, the filling bump is disposed on the base, the metal layer is disposed on the base and covers the filling bump, and the contact layer is disposed on the metal layer.

8. The microelectromechanical switching device according to claim 7, characterized in that, The hardness of the contact layer is greater than that of the metal layer.

9. The microelectromechanical switching device according to claim 7, characterized in that, The hardness of the contact layer is greater than the hardness of the signal trace.

10. The microelectromechanical switching device according to claim 4, characterized in that, The orthographic projections of the contact bump portion and the connecting portion on the second substrate overlap with the plurality of actuating electrodes, and the plurality of actuating electrodes are located inside the orthographic projections of the two supporting portions on the second substrate.

11. The microelectromechanical switching device according to any one of claims 3 to 10, characterized in that, The orthogonal projection of the plurality of first conductive vias connected by the signal traces onto the second substrate is located outside the plurality of actuation electrodes.

12. The microelectromechanical switching device according to claim 1, characterized in that, The second substrate further includes a substrate and a plurality of first conductive vias and a plurality of second conductive vias separated from each other. The plurality of first conductive vias and the plurality of second conductive vias respectively penetrate the substrate. The plurality of first conductive vias can transmit signals, and the plurality of second conductive vias are the plurality of actuation electrodes, wherein the plurality of actuation electrodes are located inside the plurality of first conductive vias. The signal traces are disposed on the substrate of the second substrate and are connected to the plurality of first conductive vias in the portion; The switch structure includes a contact bump portion, which is arranged corresponding to the signal trace to form the off state; as well as When the plurality of actuating electrodes receive the differentiated driving conditions, the switching structure gradually contacts the signal trace, thereby switching from the off state to the on state.

13. The microelectromechanical switching device according to claim 12, characterized in that, The switch structure further includes a support portion and a connecting portion. The support portion is fixed to the substrate and connected to the plurality of first conductive vias located on the side opposite to the signal trace, while the connecting portion connects the contact bump portion and the support portion.

14. The microelectromechanical switching device according to claim 13, characterized in that, The contact bump portion includes a base, a filling bump, a metal layer, and a contact layer. The base is connected to the connecting portion, the filling bump is disposed on the base, the metal layer is disposed on the base and covers the filling bump, and the contact layer is disposed on the metal layer.

15. The microelectromechanical switching device according to claim 14, characterized in that, The hardness of the contact layer is greater than that of the metal layer.

16. The microelectromechanical switching device according to claim 14, characterized in that, The hardness of the contact layer is greater than the hardness of the signal trace.

17. The microelectromechanical switching device according to any one of claims 12 to 16, characterized in that, The orthographic projection of the connecting portion onto the substrate overlaps with the plurality of actuating electrodes.

Images